Electronic equipment including computer systems frequently emit undesirable electromagnetic radiation, commonly referred to as electromagnetic interference (EMI) or electrical noise. Electrical interference is sometimes called radio-frequency interference (RFI) or electromagnetic interference (EMI). Electromagnetic interference (EMI) may be characterized as an interfering signal generated within or external to electronic equipment. Common interference sources can be video or computer monitors, interventional devices such as radio frequency (RF) ablators, communication systems, intercoms, power-line transmissions, noise from switching devices, and/or spurious radiation from oscillators, etcetera. These noise sources can in combination or singularly contribute to degradation in performance of an electronic system. Electrical interference is the disturbance to the normal or expected operation of electrical or electronic devices, equipment, and systems.
Digital x-ray detectors can be very susceptible to electro-magnetic interference (EMI) from external sources. Such interference will create artifacts in the image, sometimes to the point of making it non-diagnostic. Artifacts produced in an image can take many forms such as streaks, blurring, ghosts, and distortion, and will depend on the cause of the artifact and the particular imaging modality used. There are ways of shielding the detector from this external interference with different metals, such as aluminum, copper or mu-metal, a nickel-iron alloy that has a very high magnetic permeability. However, such materials can often not be placed in front of the x-ray detector, as they will absorb the incoming x-ray and degrade the clinical information. Thin metals can be used, but typically the effectiveness of the shielding will be degraded.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for cancelling the effects of an EMI noise source on an X-ray detector. There is also a need for an improved X-ray detector that can be dynamically controlled to operate at different line times.